Expression Of Prostaglandin E2 Receptors In Middle Ear Acquired Cholesteatoma

Objective: To investigate the expression of prostaglandin E2 receptor subtypes,E-prostanoid(EP)1-4 receptors,in acquired middle ear cholesteatoma and its possible role in the pathologic process of this disorder.Methods: Specimens from 29 patients with acquired cholesteatoma were as experimental group,and from 19 normal external auditory canal skins as controls.The expressions of EP receptors in both groups were assessed by immunohistochemistry,quantitative real-time PCR and Western Blot.Results: In acquired cholesteatoma,EP1-EP4 receptors were mainly expressed on squamous epitheliumandsubepithelialinfiltrated inflammatory cells.In external auditory canal skin,EP1-EP4 receptors were mainly expressed on squamous epithelium and glandular epithelium.The expression of EP4 receptor on mRNA and protein levels were significant lower in acquired cholesteatoma compared with controls.EP1-EP3 receptors had no significant difference between the experimental and control group.Conclusion: Low expression of EP4 may play a crucial role in the pathologic process of acquired cholesteatoma,but not EP1,EP2 or EP3 receptors.EP4 receptor might be molecular target for modulating the pathological process of acquired cholesteatoma.